# destPoint: Destination given bearing (direction) and distance In geosphere: Spherical Trigonometry

 destPoint R Documentation

## Destination given bearing (direction) and distance

### Description

Given a start point, initial bearing (direction), and distance, this function computes the destination point travelling along a the shortest path on an ellipsoid (the geodesic).

### Usage

```destPoint(p, b, d, a=6378137, f=1/298.257223563, ...)
```

### Arguments

 `p` Longitude and Latitude of point(s), in degrees. Can be a vector of two numbers, a matrix of 2 columns (first one is longitude, second is latitude) or a SpatialPoints* object `b` numeric. Bearing (direction) in degrees `d` numeric. Distance in meters `a` major (equatorial) radius of the ellipsoid. The default value is for WGS84 `f` ellipsoid flattening. The default value is for WGS84 `...` additional arguments. If an argument 'r' is supplied, this is taken as the radius of the earth (e.g. 6378137 m) and computations are for a sphere (great circle) instead of an ellipsoid (geodetic). This is for backwards compatibility only

### Value

A pair of coordinates (longitude/latitude)

### Note

Direction changes continuously when travelling along a geodesic. Therefore, the final direction is not the same as the initial direction. You can compute the final direction with `finalBearing` (see examples, below)

### Author(s)

This function calls GeographicLib code by C.F.F. Karney

### References

C.F.F. Karney, 2013. Algorithms for geodesics, J. Geodesy 87: 43-55. doi: 10.1007/s00190-012-0578-z. Addenda: https://geographiclib.sourceforge.io/geod-addenda.html. Also see https://geographiclib.sourceforge.io/

### Examples

```p <- cbind(5,52)
d <- destPoint(p,30,10000)
d

#final direction, when arriving at endpoint:
finalBearing(d, p)
```

geosphere documentation built on Nov. 16, 2022, 1:06 a.m.